Fast-low energy transfer to Earth-Moon Lagrange point L2

Patent metadata

Field	Value
Publication number	US-9284068-B2
Application number	US-201414247652-A
Country	US
Kind code	B2
Filing date	Apr 8, 2014
Priority date	Apr 8, 2014
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

A control system for a hybrid propulsion spacecraft, configured for transfer between low earth parking orbit (LEO) and a Lissajous L2 orbit (L2O), including a first control portion communicably connected to a high thrust (HT) engine portion of the hybrid propulsion spacecraft, a second control portion communicably connected to a low thrust high specific impulse (LT-HI) engine portion of the hybrid propulsion spacecraft, the first and second control portions being configured to control both the HT engine portion and the LT-HI engine portion to provide an optimal LEO to L2O transfer trajectory, wherein the optimal LEO to L2O trajectory includes an optimal LT-HI trajectory portion, selected from a stable manifold trajectory, and an optimal HT trajectory portion, and wherein the LT-HI trajectory portion and HT trajectory portion are configured for providing a combined optimal trajectory along the LEO to L2O transfer trajectory, and are optimized substantially simultaneously.

First claim

What is claimed is:

1. A control system for a hybrid propulsion spacecraft configured for transfer between low earth parking orbit (LEO) and a Lissajous L2 orbit (L2O), the control system comprising:
a first control portion communicably connected to a high thrust (HT) engine portion of the hybrid propulsion spacecraft;
a second control portion communicably connected to a low thrust high specific impulse (LT-HI) engine portion of the hybrid propulsion spacecraft; and
the first and second control portions being configured to control both the HT engine portion and the LT-HI engine portion of the hybrid propulsion spacecraft to provide an optimal LEO to L2O transfer trajectory;
wherein the optimal LEO to L2O trajectory includes an optimal LT-HI trajectory portion, selected from a stable manifold trajectory, and an optimal HT trajectory portion, and wherein the LT-HI trajectory portion and HT trajectory portion are configured for providing a combined optimal trajectory along the LEO to L2O transfer trajectory, and are optimized substantially simultaneously.

2. The system of claim 1 , wherein the LT-HI trajectory portion is a time optimal trajectory.

3. The system of claim 1 , wherein the LT-HI trajectory effects ballistic capture of the spacecraft at L2O.

4. The system of claim 1 , wherein the HT trajectory portion is at least one of a time optimal trajectory and a fuel optimal trajectory.

5. The system of claim 1 , wherein the HT trajectory portion is selected from a manifold of HT trajectories distributed between a time optimal trajectory and a fuel optimal trajectory.

6. The system of claim 1 , wherein the combined optimal trajectory is optimized with a global optimizer (GO) approach that is configured for application of hybrid propulsion in effecting the combined optimal trajectory.

7. The system of claim 6 , wherein the first and second control portions command the HT engine portion and the LT-HI engine portion and effect spacecraft transfer with hybrid propulsion along the combined optimal trajectory commencing with an initial impulse change from LEO to initiation of ballistic capture in L2O.

8. The system of claim 1 , wherein the HT trajectory portion transits between LEO and an initial point along the LT-HI trajectory portion.

9. A spacecraft comprising;
a spacecraft bus;
a hybrid propulsion system connected to the spacecraft bus, the hybrid propulsion system including a high thrust (HT) engine portion, and a low thrust high specific impulse (LT-HI) engine portion; and
a control system connected to the bus and controllably coupled to hybrid propulsion system to effect spacecraft transfer between low earth parking orbit (LEO) and a Lissajous L2 orbit (L2O), the control system being configured for generating an optimal LEO to L2O transfer trajectory employing both the HT engine portion and the LT-HI engine portion of the hybrid propulsion system;
wherein the optimal LEO to L2O trajectory includes an optimal LT-HI trajectory portion, selected from a stable manifold trajectory, and an optimal HT trajectory portion, and wherein the LT-HI trajectory portion and HT trajectory portion are configured for providing a combined optimal trajectory along the LEO to L2O transfer trajectory, and are optimized substantially simultaneously.

10. The system of claim 9 , wherein the LT-HI trajectory portion is a time optimal trajectory.

11. The system of claim 9 , wherein the LT-HI trajectory effects ballistic capture of the spacecraft at L2O.

12. The system of claim 9 , wherein the HT trajectory portion is at least one of a time optimal trajectory and a fuel optimal trajectory.

13. The system of claim 9 , wherein the HT trajectory portion is selected from a manifold of HT trajectories distributed between a time optimal trajectory and a fuel optimal trajectory.

14. The system of claim 9 , wherein the combined optimal trajectory is optimized with a global optimizer (GO) approach that is configured for application of hybrid propulsion in effecting the combined optimal trajectory.

15. The system of claim 14 , wherein the first and second control portions command the HT engine portion and the LT-HI engine portion and effect spacecraft transfer with hybrid propulsion along the combined optimal trajectory commencing with an initial impulse change from LEO to initiation of ballistic capture in L2O.

16. The system of claim 9 , wherein the HT trajectory portion transits between LEO and an initial point along the LT-HI trajectory portion.

17. A method for generating a thrusting profile for a hybrid propulsion spacecraft for transfer between low earth orbit (LEO) and a Lissajous L2 orbit (L2O), the method comprising the steps of:
computing a stable manifold (SM) of trajectories leading to L2O based on thrust generated with a low thrust high specific impulse (LT-HI) engine of the hybrid propulsion spacecraft;
generating a high thrust (HT) trajectory between LEO and at least one trajectory of the SM, wherein the HT trajectory is generated based at least in part with an impulse change provided by an HT engine of the hybrid propulsion spacecraft, and wherein the HT trajectory and the at least one SM trajectory form a combined trajectory from LEO to L2O; and
optimizing the combined trajectory over both the HT trajectory and the at least one trajectory of the SM in combination and generating a combined optimal trajectory from LEO to L2O.

18. The method of claim 17 , further comprising selecting the HT trajectory from a manifold of HT trajectories distributed between a time optimal trajectory and a fuel optimal trajectory.

19. The method of claim 17 , further comprising optimizing the combined optimal trajectory with a global optimizer (GO) approach that is configured for application of hybrid propulsion in effecting the combined optimal trajectory.

20. The method of claim 19 , further comprising commanding the HT engine portion and the LT-HI engine portion with a first and second control portion of the hybrid propulsion spacecraft and effecting spacecraft transfer with hybrid propulsion along the combined optimal trajectory commencing with an initial impulse change from LEO to initiation of ballistic capture in L2O.

Assignees

• Boeing Co

Inventors

• Post Kevin E
• Belbruno Edward

Classifications

• B64G1/10 Primary

  Artificial satellites; Systems of such satellites; Interplanetary vehicles (space shuttles B64G1/14) · CPC title

• B64G1/2422

  using Lagrange points, e.g. halo orbits · CPC title

• B64G1/2427

  Transfer orbits · CPC title

• B64G1/40 Primary

  Arrangements or adaptations of propulsion systems · CPC title

• B64G1/242 Primary

  Orbits and trajectories · CPC title